Flushing method notifies the base class that the pin has started or stopped flushing.
void Flushing( BOOL bInProgress );
Specifies a Boolean value that indicates whether the pin is flushing. Use the value TRUE when the pin begins a flush operation, and FALSE when the pin ends a flush operation.
This method does not return a value.
This method causes the CBaseStreamControl::CheckStreamState method to stop waiting. While the pin is flushing, CheckStreamState always returns STREAM_DISCARDING.